Nitric acid leaked into the Rhine from a cargo vessel at the Bayer chemical company's wharf at Krefeld, west Germany, early Wednesday, sending out fumes and causing a fire on board, the company said.

People living in the nearby Uerdingen district were warned to keep their windows and doors closed because of the fumes, but no-one was hurt and checks for contamination of the air showed no danger for humans, the statement added.

The barge was carrying some 1,800 tonnes of nitric acid, a feedstock in the production of polyurethane, the statement from Bayer's Krefeld-Uerdingen plant said -- Germany (AFP)